Battery management system

ABSTRACT

Vehicle battery management systems (BMS) and methods are described, in which the output of a vehicle battery is reduced by activating a shutdown mode. A BMS may be configured to start a timer when the vehicle is turned off, e.g. based on when the main power between the vehicle and the battery is interrupted or based on a signal from the vehicle control system. The BMS may further be configured to store BMS data (e.g. variable data related to operation and/or status of the battery) to an electronic storage device, and to switch the battery to a shutdown mode, when the timer reaches a predetermined value. The BMS may be further configured to load the BMS data from the electronic storage device and/or to deactivate the shutdown mode when the vehicle is turned back on.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. Nonprovisionalappplication Ser. No. 15/190,455, filed on Jun. 23, 2016, which claimspriority to U.S. Provisional Patent Application No. 62/272,709, filed onDec. 30, 2015, entitled BATTERY MANAGEMENT SYSTEM, the entiredisclosures of which are incorporated by reference for all purposes.

BACKGROUND

Exemplary embodiments of the present disclosure relate to batterymanagement systems that may be used, for example, for managing poweroutput and modes of one or more batteries in an electric vehicle.

An electric vehicle uses a battery pack as an energy source. To ensurethat the electric vehicle operates properly, the battery pack ismonitored and managed during discharge and charging, e.g. to maintainthe battery pack within a certain range of temperature and otherparameters. Operating within the working temperature ensures that thebattery pack performs efficiently and has a long service life. Due tothe large influence of temperature on the performance and the servicelife of the battery pack, the working temperature of the battery packand the consistency of the working states of the battery cells withinthe battery pack are very important in the design of the electricvehicle and the battery pack. As such a battery management system (BMS)is typically used to manage the performance and operation of arechargeable battery (e.g. a cell or battery pack), by protecting thebattery from operating outside its working temperature, monitoring itsstate, and calculating and/or reporting data to other control systems inthe vehicle. The BMS may also control recharging of the battery, e.g. byredirecting recovered or charger energy to the battery pack.

When an electrical vehicle is turned off, may maintain operation of atleast some electrical subsystems that slowly drain the battery. This canresult, for example, in “leakage” of 13 mA-4 mA of current from thebattery.

SUMMARY

Exemplary embodiments of the present disclosure may address at leastsome of the above-noted problems. For example, according to firstaspects of the disclosure, a vehicle battery management system (BMS) maybe configured to start a timer when the vehicle is turned off, e.g.based on when the main power between the vehicle and the battery isinterrupted or based on a signal from the vehicle control system. TheBMS may further be configured to store BMS data (e.g. variable datarelated to operation and/or status of the battery) to an electronicstorage device, and to switch the battery to a shutdown mode, when thetimer reaches a predetermined value (or expires if configured as acountdown timer). In embodiments, the BMS may be further configured toload the BMS data from the electronic storage device and/or todeactivate the shutdown mode when the vehicle is turned back on, e.g.based on the main power between the vehicle and the battery beingreactivated, and/or a signal from the vehicle control system indicatingthat the vehicle is turned “on.”

According to further aspects of the invention, a vehicle batterymanagement system (BMS), may include one or more of a main powermonitor, a counter and/or a controller including a microprocessor. Themain power monitor may be configured to determine when main powerbetween a vehicle and a battery is detected, and/or when the main powerbetween the vehicle and the battery is not detected. The counter may beconfigured to begin counting based at least in part on the main powermonitor determining that the main power between the vehicle and thebattery is not detected. The controller may be configured to store BMSdata to an electronic storage device and to switch the battery to ashutdown mode based at least in part on the counter reaching apredetermined value. In embodiments, the controller may be furtherconfigured to load the BMS data from the electronic storage deviceand/or to deactivate the shutdown mode based at least in part on themain power monitor determining that the main power between the vehicleand the battery is detected.

In embodiments, the predetermined value may correspond to a time in arange between 12 hours and 36 hours; or to a time of about 24 hours.

In embodiments, the shutdown mode may limit a current from the batteryto about 1 mA or less.

In embodiments, the BMS may be included in a battery pack including thebattery, or it may be included in other control system(s) of the vehicle(or combinations thereof).

In embodiments, the controller may be configured to reset the counterbased at least in part on the main power monitor determining that themain power between the vehicle and the battery is restored beforeactivation of the shutdown mode.

In embodiments, the controller may be configured to adjust thepredetermined value for the counter when the counter is reset based onthe main power monitor determining that the main power between thevehicle and the battery is restored before activation of the shutdownmode.

In embodiments, the controller may be configured to switch the batteryto a standby mode based at least in part on the main power monitordetermining that the main power between the vehicle and the battery isnot detected, the standby mode limiting a current from the battery to arange of about 6 mA to 2 mA.

According to further aspects of the invention, an electric vehicle maybe provided including a battery; an electric motor configured to bepowered by the battery; and a vehicle battery management system (BMS).In embodiments, the BMS may include a main power monitor, configured todetermine when main power between the vehicle and the battery isdetected, and when the main power between the vehicle and the battery isnot detected; a counter, configured to begin counting based at least inpart on the main power monitor determining that the main power betweenthe vehicle and the battery is not detected; and a controller,configured to store BMS data to an electronic storage device and toswitch the battery to a shutdown mode based at least in part on thecounter reaching a predetermined value. In embodiments, the controllermay be configured to load the BMS data from the electronic storagedevice and to deactivate the shutdown mode based at least in part on themain power monitor determining that the main power between the vehicleand the battery is detected.

In embodiments, the controller may be configured to switch the batteryto a standby mode based at least in part on the main power monitordetermining that the main power between the vehicle and the battery isnot detected, the standby mode limiting a current from the battery to arange of, for example, about 6 mA to 2 mA.

In embodiments, the controller may be configured to control operatingparameters of the battery during a working mode in which power isprovided from the battery to the motor.

Additional features, advantages, and embodiments of the invention may beset forth or apparent from consideration of the following detaileddescription, drawings, and claims. Moreover, it is to be understood thatboth the foregoing summary of the invention and the following detaileddescription are exemplary and intended to provide further explanationwithout limiting the scope of the invention claimed. The detaileddescription and the specific examples, however, indicate only preferredembodiments of the invention. Various changes and modifications withinthe spirit and scope of the invention will become apparent to thoseskilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention, are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the detailed description serve to explain the principlesof the invention. No attempt is made to show structural details of theinvention in more detail than may be necessary for a fundamentalunderstanding of the invention and various ways in which it may bepracticed. In the drawings:

FIG. 1 is a schematic diagram of an exemplary electric vehicle motorefficiency control system according to aspects of the presentdisclosure.

FIG. 2 is a schematic diagram of an exemplary battery pack according toaspects of the present disclosure.

FIG. 3 is a schematic diagram of an exemplary BCM according to aspectsof the present disclosure.

FIG. 4 is a partial circuit diagram of an exemplary BCM subsystemaccording to aspects of the present disclosure.

FIG. 5 is a flow diagram depicting aspects of an exemplary batterymanagement method according to aspects of the present disclosure.

FIG. 6 is a flow diagram depicting aspects of another exemplary batterymanagement method according to aspects of the present disclosure.

DETAILED DESCRIPTION

Various example embodiments of the present disclosure will be describedbelow with reference to the drawings constituting a part of thedescription. It should be understood that, although terms representingdirections are used in the present disclosure, such as “front”, “rear”,“upper”, “lower”, “left”, “right”, and the like, for describing variousexemplary structural parts and elements of the present disclosure, theseterms are used herein only for the purpose of convenience of explanationand are determined based on the exemplary orientations shown in thedrawings. Since the embodiments disclosed by the present disclosure canbe arranged according to different directions, these terms representingdirections are merely used for illustration and should not be regardedas limiting. Wherever possible, the same or similar reference marks usedin the present disclosure refer to the same components.

Unless defined otherwise, all technical terms used herein have the samemeanings as commonly understood by one of ordinary skill in the art towhich the invention pertains. The embodiments of the invention and thevarious features and advantageous details thereof are explained morefully with reference to the non-limiting embodiments and examples thatare described and/or illustrated in the accompanying drawings anddetailed in the following description. It should be noted that thefeatures illustrated in the drawings are not necessarily drawn to scale,and features of one embodiment may be employed with other embodiments asthe skilled artisan would recognize, even if not explicitly statedherein. Descriptions of well-known components and processing techniquesmay be omitted so as to not unnecessarily obscure the embodiments of theinvention. The examples used herein are intended merely to facilitate anunderstanding of ways in which the invention may be practiced and tofurther enable those of skill in the art to practice the embodiments ofthe invention. Accordingly, the examples and embodiments herein shouldnot be construed as limiting the scope of the invention, which isdefined solely by the appended claims and applicable law. Moreover, itis noted that like reference numerals reference similar parts throughoutthe several views of the drawings.

As used herein, the use of the terms “about” or “approximately” shouldbe interpreted as within 20% of a given value, unless otherwisespecified. The term “substantially” should be interpreted asencompassing greater than 75% of a thing, e.g. a component that is made“substantially” of plastic would comprise greater than 75plastic.

FIG. 1 is a schematic diagram of an exemplary electric vehicle motorefficiency control system according to aspects of the presentdisclosure. As shown in FIG. 1, a control system for controlling anelectric vehicle may include a battery pack 110, a motor driving circuit103, a motor 104, a sensor 105, a center console 106 (including a CPU109), a driving input system 107, a memory 108 and the like. The batterypack 110 provides the motor 104 with operating power; the motor drivingcircuit 103 may be connected between the motor 104 and the battery pack110 to transmit the power of the battery pack 110 to the motor 104, andthe working state of the motor 104 may be controlled by controlling thevoltage/current transmitted to the motor 104. The sensor 105 may be usedfor sensing the current operating parameters (e.g. the speed and thetorque) of the motor 104 and sending the operating parameters to thecenter console 106. According to these parameters, the center console106 can judge the current operating state of the motor 104 and send acontrol signal to the motor driving circuit 103 to change thevoltage/current input to the motor 104, thus changing the operatingstate of the motor. The center console 106 may be further connected withthe driving input system 107 and the memory 108. The driving inputsystem 107 may be configured to input the target operating state of themotor 104 to the center console 106, the memory 108 may be used to storea motor operational model, and the center console 106 may be configuredto read data from and write data into the motor operational model.

In embodiments, the battery pack 110 (and/or motor driving circuit 103or CPU 109) may be configured with a BMS as described herein. Furtherdetails of an exemplary battery pack are shown in FIG. 2.

FIG. 2 is a schematic diagram of an exemplary battery pack 210 accordingto aspects of the present disclosure. As shown in FIG. 2, battery pack210 may include a number of BMS 205 a-205 c, each configured to manageseparate batteries or cells (not shown). Battery pack 201 includesfeatures that allow data communication between the battery pack 210 andother control subsystems, such as discussed herein. It is noted that theconfiguration depicted in FIG. 2 is merely exemplary, and that theinformation gathering and processing discussed herein can be implementedin various other ways.

As shown in FIG. 2, the EMS (Energy Management System) 220 collectsmodular information 215 from BMS (Battery Management System) 205 a-205c, calculates and integrates the data 225, and then sends the resultsfrom the calculation(s) to VCU (Vehicle Control Unit) 230 for furtherjudgments and/or control operations. In some examples, the battery pack210 can implement a master-slave communication structure. EMS 220 canaccumulate and collect all the data 215 from each BMS 205 a-205 c onevery module, and perform data calculation and treatment. By way offurther example, battery pack 210 can communicate with the VCU 230responsive to the vehicle being activated (e.g. detecting main powerbetween the battery and the vehicle). The battery pack 210 can alsocommunicate with a charger (not shown) responsive to the vehicle beingcharged. The battery pack 210 may also communicate with a maintenancecomputer (not shown) responsive to UI or other software applicationbeing connected to the battery pack, e.g. to facilitate maintenance,diagnostics, etc. Additional details regarding the configuration of anindividual BMS are shown in FIG. 3.

As shown in FIG. 3, exemplary BMS 305 may include one or more of a mainpower monitor 310, a counter 315, a battery pack initialization module320, a battery pack mode switching module 325, a battery temperaturesenor module 330, and/or a motor temperature senor module 340. Each ofthe components shown in FIG. 3 may be communicatively connected to oneanother (or other control subsystems) via a bus, or other wired orwireless communication link. Although described in the context of a BMS305 that is integrated in a battery pack (e.g. battery pack 210), inother examples, one of more of these components may be distributed amongvarious other control components or subsystems discussed herein.

In embodiments, the main power monitor 310 may be configured as hardwareand/or software that detects when a main power (e.g. 12V) is established(or discontinued) between the vehicle and the battery that the BMS 305is managing. This may reflect, for example, the vehicle being turned“on” by a driver (for establishing), or the vehicle being turned “off”by the driver (for discontinuing). In some examples, the main powermonitor 310 (or separate charging module) may be configured as hardwareand/or software that detects when a charging power is established (ordiscontinued) between a vehicle charger and the battery that the BMS 305is managing. It is also noted that, in some examples, the vehiclecontrol system may generate signals that replace and/or supplement thefunction of the main power monitor 310. For example, the vehicle controlsystem may generate signals based on the vehicle being turned “on” or“off,” and/or the vehicle control system may monitor the main power ifthe vehicle independently.

In embodiments, the counter 315 may be configured as hardware and/orsoftware that responds to signals from the main power monitor (or othersignal representing when the vehicle is turned “on” or “off”), andprovides data to the battery pack initialization module 320 and/or thebattery pack mode switching module 325. For example, the counter 315 maybe configured to begin counting based at least in part on the main powermonitor 310 determining that the main power between the vehicle and thebattery is not detected. The counter 315 may take many forms, includingvarious timing mechanisms and/or software routines. The BMS 305 may beconfigured to store BMS data to an electronic storage device (not shown)and/or to switch the battery to a shutdown mode based at least in parton the counter reaching a predetermined value. For example, the counter315 may send counting data to the battery pack mode switching module325, and the battery pack mode switching module 325 may be configured toinitiate storage of the BMS data and/or switching the battery to ashutdown mode upon the counter reaching a predetermined value, such asthe counter corresponding to a time in a range between 12 hours and 36hours; or to a time of about 24 hours. Storing the BMS data prior toshutdown may be beneficial in allowing various subsystems to shut downwithout the loss of data that is necessary or beneficial forreactivation of the BMS and/or battery. By storing such data, energyrequirements from the battery are thus reduced. In some examples, theshutdown mode may limit a current from the battery to about 1 mA orless.

In some examples, the a battery pack mode switching module 325 may alsobe configured to switch the battery to a standby mode based at least inpart on the main power monitor 310 determining that the main powerbetween the vehicle and the battery is not detected. The standby modemay, for example, limit battery output to certain systems, and maygenerally limit a current from the battery to a range of about 6 mA to 2mA. In some examples, the standby mode may be further based on thecounter 315 reaching a second predetermined value, which is less thatthe value for initiating the shutdown mode. For example, the standbymode may be initiated when the counter corresponds to a time of about 1minute (or some multiple of minutes less than an hour), and the shutdownmode may be initiated when the counter corresponds to some number ofhours (e.g. about 24 hours).

In some examples, the a battery pack mode switching module 325 (or thecounter 315) may also be configured to reset the counter 315, e.g. whenthe main power monitor 310 detects reestablishment of the main powerbetween the vehicle and the battery while the counter 310 is running.For example, the battery pack mode switching module 325 may beconfigured to send a reset signal to the counter 315, or the counter 315may be configured to automatically reset based on a signal from the mainpower monitor 310.

In some examples, the a battery pack mode switching module 325 (orcounter 315) may also be configured to adjust the predetermined countervalues used to initiate the shutdown and/or standby modes. For example,if the main power monitor 310 detects reestablishment of the main powerbetween the vehicle and the battery while the counter 310 is running,the predetermined times for initiating the shutdown and/or standby modesmay be reduced by a percentage (e.g. 10%, 25% or 50%), by an amountbased on the time that the main power between the vehicle and thebattery is reestablished for, a portion of the time already counted,etc. This may be beneficial, for example, when the main power betweenthe vehicle and the battery is only reestablished for a brief period oftime, which may indicate that the vehicle has not been fully operatedand shutdown or standby modes may be implemented without waiting foranother full counter cycle.

In embodiments, the battery pack initialization module 320 may beconfigured to load the BMS data from the electronic storage deviceand/or to deactivate the shutdown (or standby) mode based at least inpart on the main power monitor 310 determining that the main powerbetween the vehicle and the battery is detected.

The BMS 305 may further include a battery temperature senor module 330,a motor temperature senor module 340, and various other modules relatedto monitoring and managing the operation of the battery being managed.For example, the battery temperature senor module 330 may be used tolimit the output of the battery to maintain the operating temperature ofthe battery, and motor temperature senor module 340 may be used tomanage battery heat dissipation functions. The BMS 305 may be configuredto monitor and manage a range of battery-related functions, such asmonitoring current in or out of the battery, the state of the battery,total voltage, voltages of individual cells, minimum and maximum cellvoltage, average temperature, coolant intake temperature, coolant outputtemperature, temperatures of individual cells, state of charge, depth ofdischarge, etc. Additionally, the BMS 305 may be configured to calculatevarious values, such as maximum charge current, maximum dischargecurrent, energy (kW) delivered since last charge or charge cycle,internal impedance of a cell, charge (A) delivered or stored, totalenergy delivered since first use, total operating time since first use,total number of cycles, etc. In some examples, any number of thedetected or calculated values mentioned above may be stored (andretrieved) as BMS data.

The BMS 305 may be configured to protect the battery being managed bypreventing (or inhibiting) it from operating outside its safe operatingarea, such as preventing over-current, over-voltage (e.g. duringcharging), under-voltage (e.g. during discharging), over-temperature,under-temperature, over-pressure, ground fault or leakage current, etc.Additional details regarding an exemplary circuit diagram for anindividual BMS are shown in FIG. 4.

As shown in FIG. 4, BMS 305 may include circuitry 400 that provides mainpower 410 from the battery 420 to a vehicle (e.g. 12V), as well as aplurality of low-voltage control signal lines and monitoring channels430-450, e.g. for communicating with a microcontroller (MCU), detectingconditions of the vehicle and/or battery. In some examples, a mcu carcondition signal may be used in conjunction with the counter to initiateor cancel a shutdown (or standby mode). For example, when:mcu_car_condition=hi and the counter ≥24; then the BMS data may besaved, the battery pack switched to shutdown mode, and the counter resetto 0. Or, while in shutdown mode: when: mcu_car_condition=low and thecounter=0; then the battery pack may be activated, and the BMS dataretrieved and loaded back to the MCU.

FIGS. 5 and 6 show flow diagrams of exemplary battery management methodsaccording to aspects of the present invention. Each operation depictedtherein may represent a sequence of operations that can be implementedin hardware or computer instructions implemented in hardware. In thecontext of computer instructions, the operations representcomputer-executable instructions stored on one or more computer-readablestorage media that, when executed by one or more physical processors,perform the recited operations. Generally, computer-executableinstructions include routines, programs, objects, components, and thelike that perform particular functions or implement particular datatypes. The order in which the operations are described is not intendedto be construed as a limitation, and any number of the describedoperations can be combined in any order and/or in parallel to implementthe processes. Additionally, any specific reference to one or moreoperations being capable of being performed in a different order is notto be understood as suggesting that other operations may not beperformed in another order.

As shown in FIG. 5, a battery management method may include operationsrelated to determining whether to enter a shutdown mode. The flow maybegin with 510, in which a battery pack is initialized. This mayinclude, for example, activating the battery via BMS or other controlsystem, connecting the battery with the vehicle powertrain, and/orloading BMS data from a storage device in to RAM or other memory of anMCU. Initialization may also include various status checks and/ordiagnostic routines to determine the health of the battery, etc. Oncethe battery is initialized, a check may be performed that confirmsand/or monitors the presence of main power between the battery and thevehicle. The flow may proceed with 520.

In 520, the BMS receives a signal from the vehicle controller, or othersubsystem, reflecting, for example, that the vehicle has been turnedoff, that main power between the vehicle and the battery has beeninterrupted (or reduced to a predetermined threshold), and/or batterycharging has been completed. As discussed further herein, this may come,for example, from a main power monitor, BMS, or vehicle control system.The flow may proceed with 530.

In 530, a timing routine may be initiated based on the signal receivedin 520. This may include, for example, initiating a counter, or othertimer, that measures the time during which the vehicle is in an “off”state, and/or during which the main power between the vehicle and thebattery is absent. During 530, various monitoring routines may also beexecuted, e.g. to determine whether the vehicle is switched to an “on”state, and/or if the main power between the vehicle and the battery isreestablished. If such monitoring routines, or appropriate signal(s),reflect that the vehicle is switched to an “on” state, and/or if themain power between the vehicle and the battery is reestablished, theflow may return to 510, in which the battery is reinitialized, e.g. byresetting the counter, loading the BMS data from storage, and/oractivating the battery, as necessary. In some examples, 530 may also beresponsive to a signal indicating that battery charging has commenced,and return to 510 until charging is completed.

If the timing routine reaches a predetermined value during 530 (i.e.without returning to 510), the flow may proceed to 540. Thepredetermined value may be, for example, a counter value correspondingto a matter of hours, e.g. a time between 12 hours to 36 hours, or about24 hours. In some examples, the predetermined value may be adjusted bythe BMS based on various criteria, such as how long the vehicle was inthe “on” state, how long a previous timing sequence 530 lasted, whetherthe signal in 520 reflected the vehicle being turned off, main powerbetween the vehicle and the battery being interrupted (or reduced to apredetermined threshold), and/or battery charging completed, etc.

In 540, the BMS may initiate a battery shutdown mode, including, forexample, storing BMS data in an electronic storage device, andactivating a shutdown mode, e.g. in which current from the battery isreduced, or limited, to about 1 mA or less. In some examples, certainbatteries and/or cells may be managed by one or more BMS in differentways during shutdown operation. For example, when multiple batteriesand/or cells are available, one of them may be used to continueproviding power to one or more subsystems, while others are shut downcompletely. In some examples, the BMS may be configured to cycledifferent batteries and/or cells to different shutdown levels, e.g. todistribute any necessary “leakage” to different batteries at differenttimes, and/or based on individual battery states.

The shutdown mode may continue, for example, until a signal reflectingthat the vehicle has been turned on, that main power between the vehicleand the battery has been restored (or increased to a predeterminedthreshold), and/or battery charging has been initiated, at which pointthe flow may return to battery initialization in 510.

As shown in FIG. 6, another battery management method may includeoperations related to determining whether to enter a standby mode,followed by a more restrictive shutdown mode. The flow may begin with610, in which a battery pack is initialized. This may include, forexample, activating the battery via BMS or other control system,connecting the battery with the vehicle powertrain, and/or loading BMSdata from a storage device in to RAM or other memory of an MCU.Initialization may also include various status checks and/or diagnosticroutines to determine the health of the battery, etc. Once the batteryis initialized, a check may be performed that confirms and/or monitorsthe presence of main power between the battery and the vehicle. The flowmay proceed with 620.

In 620, the BMS receives a signal from the vehicle controller, or othersubsystem, reflecting, for example, that the vehicle has been turnedoff, that main power between the vehicle and the battery has beeninterrupted (or reduced to a predetermined threshold), and/or batterycharging has been completed. As discussed further herein, this may come,for example, from a main power monitor, BMS, or vehicle control system.The flow may proceed with 630.

In 630, a first timing routine may be initiated based on the signalreceived in 620. This may include, for example, initiating a counter, orother timer, that measures the time during which the vehicle is in an“off” state, and/or during which the main power between the vehicle andthe battery is absent or reduced to a predetermined level. During 630,various monitoring routines may also be executed, e.g. to determinewhether the vehicle is switched to an “on” state, and/or if the mainpower between the vehicle and the battery is reestablished. If suchmonitoring routines, or appropriate signal(s), reflect that the vehicleis switched to an “on” state, and/or if the main power between thevehicle and the battery is reestablished, the flow may return to 610, inwhich the battery is reinitialized, e.g. by resetting the counter,loading the BMS data from storage, and/or activating the battery, asnecessary. In some examples, 630 may also be responsive to a signalindicating that battery charging has commenced, and return to 610 untilcharging is completed.

If the first timing routine reaches a first predetermined value during630 (i.e. without returning to 610), the flow may proceed to 640. Thefirst predetermined value may be, for example, a counter valuecorresponding to a matter of minutes, e.g. a time between 1 to 10minutes, or 5 minutes, an hour, or other time that is less than thesecond predetermined value discussed further below. In some examples,the first predetermined value may be adjusted by the BMS based onvarious criteria, such as operational information about the vehicle,e.g. the average speed or recurring stops of the vehicle, battery stateinformation, whether the signal in 620 reflected the vehicle beingturned off, main power between the vehicle and the battery beinginterrupted (or reduced to a predetermined threshold), and/or batterycharging completed, etc.

In 640, the BMS may initiate a battery standby mode, including, forexample, deactivating certain vehicle subsystems, or otherwise reducingor limiting current from the battery to about 6 mA to 2 mA. In someexamples, certain batteries and/or cells may be managed by one or moreBMS in different ways during standby mode. For example, when multiplebatteries and/or cells are available, one of them may be used tocontinue providing power to one or more subsystems, while others aredeactivated (or placed in a shutdown mode as described further herein).In some examples, the BMS may be configured to cycle different batteriesand/or cells to different standby and/or shutdown levels, e.g. todistribute any necessary “leakage” to different batteries at differenttimes, and/or based on individual battery states. For example, if astandby mode is indicated, a battery having the greatest charge may beselected to enter the standby mode, powering necessary subsystems, whileone or more other batteries are placed in shutdown mode.

In 650, a second timing routine may be initiated (or the first timingroutine continued). This may include, for example, reinitiating (orcontinuing to monitor) the counter, or other timer, that continues tomeasure the time during which the vehicle is in the “off” state, and/orduring which the main power between the vehicle and the battery isabsent or reduced to a predetermined level. During 650, variousmonitoring routines may also be executed, e.g. to determine whether thevehicle is switched to an “on” state, and/or if the main power betweenthe vehicle and the battery is reestablished. If such monitoringroutines, or appropriate signal(s), reflect that the vehicle is switchedto an “on” state, and/or if the main power between the vehicle and thebattery is reestablished, the flow may return to 610, in which thebattery is reinitialized, e.g. by resetting the counter, loading the BMSdata from storage, and/or activating the battery, as necessary. In someexamples, 650 may also be responsive to a signal indicating that batterycharging has commenced, and return to 610 until charging is completed.

If the second timing routine 650 reaches a second predetermined valueduring 650 (i.e. without returning to 610), the flow may proceed to 660.The predetermined value may be, for example, a counter valuecorresponding to a matter of hours, e.g. a time between 12 hours to 36hours, or about 24 hours (inclusive or exclusive of the firstpredetermined value). In some examples, the second predetermined valuemay be adjusted by the BMS based on various criteria, such as the stateof an individual battery being managed, how long the vehicle was in the“on” state, how long a previous timing sequence 650 lasted, whether thesignal in 620 reflected the vehicle being turned off, main power betweenthe vehicle and the battery being interrupted (or reduced to apredetermined threshold), and/or battery charging completed, etc.

In 660, the BMS may initiate a battery shutdown mode, including, forexample, storing BMS data in an electronic storage device, andactivating a shutdown mode, e.g. in which current from the battery isreduced, or limited, to about 1mA or less. In some examples, certainbatteries and/or cells may be managed by one or more BMS in differentways during shutdown operation, as discussed previously.

The shutdown mode 660 may continue, for example, until a signalreflecting that the vehicle has been turned on, that main power betweenthe vehicle and the battery has been restored (or increased to apredetermined threshold), and/or battery charging has been initiated, atwhich point the flow may return to battery initialization in 610.

The present disclosure further provides an electric vehicle using theabove-mentioned battery management systems and methods, the other partsof the electric vehicle can adopt the structure of existing electricvehicles, with a battery management system as described herein, and willnot be repeated redundantly.

Although the present disclosure has been described with reference to thespecific embodiments shown in the drawings, it should be understood thatthe lightweight fastening methods provided by the present disclosure canhave a variety of variations without departing from the spirit, scopeand background of the present disclosure. The description given above ismerely illustrative and is not meant to be an exhaustive list of allpossible embodiments, applications or modifications of the invention.Those of ordinary skill in the art should be still aware that,parameters in the embodiments disclosed by the present disclosure can bechanged in different manners, and these changes shall fall within thespirit and scope of the present disclosure and the claims. Thus, variousmodifications and variations of the described methods and systems of theinvention will be apparent to those skilled in the art without departingfrom the scope and spirit of the invention.

What is claimed is:
 1. A vehicle battery management system (BMS),comprising: a main power monitor configured to detect a main powerbetween a vehicle and a battery; a counter, configured to begin countingwhen the main power between the vehicle and the battery is not detectedby the main power monitor; and a controller, configured to store BMSdata to an electronic storage device and to switch the battery to ashutdown mode when the counter reaches a predetermined value, and loadthe BMS data from the electronic storage device when the main powerbetween the vehicle and the battery is detected by the main powermonitor.
 2. The system of claim 1, wherein the predetermined valuecorresponds to a time period in a range between 12 hours and 36 hours.3. The system of claim 2, wherein the predetermined value corresponds toa time period of about 24 hours.
 4. The system of claim 1, wherein theshutdown mode limits a current from the battery to about 1 mA or less.5. The system of claim 1, wherein the BMS is included in a battery packincluding the battery.
 6. The system of claim 1, wherein the controlleris further configured to reset the counter when the main power betweenthe vehicle and the battery is restored before the shutdown mode isdeactivated.
 7. The system of claim 6, wherein the controller is furtherconfigured to adjust the predetermined value for the counter when thecounter is reset when the main power between the vehicle and the batteryis restored before the shutdown mode is deactivated.
 8. The system ofclaim 1, wherein the controller is further configured to switch thebattery to a standby mode based when the main power between the vehicleand the battery is not detected by the power monitor, the standby modelimiting a current from the battery to a range of about 6 mA to 2 mA. 9.An electric vehicle, comprising: a battery; an electric motor configuredto be powered by the battery; and a vehicle battery management system(BMS), including: a main power monitor configured to detect a main powerbetween a vehicle and a battery; a counter, configured to begin countingwhen the main power between the vehicle and the battery is not detectedby the main power monitor; and a controller, configured to store BMSdata to an electronic storage device and to switch the battery to ashutdown mode when the counter reaches a predetermined value, and loadthe BMS data from the electronic storage device when the main powerbetween the vehicle and the battery is detected by the main powermonitor.
 10. The vehicle of claim 9, wherein the predetermined valuecorresponds to a time period in a range between 12 hours and 36 hours.11. The vehicle of claim 10, wherein the predetermined value correspondsto a time period of about 24 hours.
 12. The vehicle of claim 9, whereinthe shutdown mode limits a current from the battery to about 1 mA orless.
 13. The vehicle of claim 9, wherein the BMS is included in abattery pack including the battery.
 14. The vehicle of claim 9, whereinthe controller is further configured to reset the counter when the mainpower between the vehicle and the battery is restored before theshutdown mode is deactivated.
 15. The vehicle of claim 14, wherein thecontroller is further configured to adjust the predetermined value forthe counter when the counter is reset based on the main power monitordetermining that the main power between the vehicle and the battery isrestored before activation of the shutdown mode.
 16. The vehicle ofclaim 9, wherein the controller is further configured to switch thebattery to a standby mode when the main power between the vehicle andthe battery is not detected by the power monitor, the standby modelimiting a current from the battery to a range of about 6 mA to 2 mA.17. The vehicle of claim 9, wherein the controller is further configuredto control operating parameters if the battery during a working mode inwhich power is provided from the battery to the motor.
 18. A method ofmanaging output of a vehicle battery, comprising: monitoring a powerstate of a vehicle; detecting a first change in the power state of thevehicle reflecting at least one of the vehicle being turned off or abattery charging being completed; starting a counter based at least inpart on the detection of the first change in the power state of thevehicle; storing BMS data to an electronic storage device, and switchingthe battery to a shutdown mode when the counter reaches a predeterminedvalue; detecting a second change in the power state of the vehiclereflecting at least one of the vehicle being turned on or a batterycharging being initiated; loading the BMS data from the electronicstorage device and deactivating the shutdown mode when detecting thesecond change in the power state of the vehicle.
 19. The method of claim18, wherein the predetermined value corresponds to a time period in arange between 12 hours and 36 hours.
 20. The method of claim 19, whereinthe predetermined value corresponds to a time period of about 24 hours.